A recent study revealed a worrying fact about ICU patients: within days, the contents of their microbiome had changed. Patients were found to have less helpful bacteria (and a diminished diversity of good bacteria species) as well as an increased amount of harmful pathogens.
Antibiotics, blood pressure medications, and lack of nutrition were all cited as potential factors leading to these potentially dangerous changes. The hyper-sanitized hospital environment (though a necessity) may also play a role.
Though similar studies had been conducted in the past, this was the most expansive, covering over 100 patients in hospitals all around the United States and Canada--comparing the microbial content of their stool samples after two days in the ICU, and the content of their stool samples after ten days. Stool samples from a healthy, non-hospitalized group of subjects were also considered as a control.
Even patients who had spent two days in the ICU showed bacteria counts that differed significantly from their non-hospitalized counterparts--and the differences after ten days were astounding.
Scientists do hope that one day, continued study of the human microbiome will give us the tools we need to understand these dramatic changes in the microbiome during hospital stays and what affect, if any, they have on patient outcomes and overall health. Additionally, if needed, therapies may be developed in order to keep such bacteria at normal levels even when conditions are challenging.